Steam-boiler filter



(No Model.)

' J. W. HYATT.

STEAM BOILER FILTER. N0. 35 6,131. Patented Jan; 18, 1887-.

N. PETEl-S, PhnloLilhograyhcr. Washington. D. C'-

- the filter.

- UNITED STATES PATENT Fries.

JOHN W'. HYATT, OF NEWARK, NEW JERSEY.

STEAM-BOILER FILTER.

SPECIFICATION forming part of Letters Patent No. 356,131, dated January18, 1887,

' Application filed May 27, 1886. Serial No. 263,366. (No model.)

To rtZZ whom it may concern.-

Be it known that I, JOHN W. HYATT, a citizen of the United States,residing in Newark, Essex county, New Jersey, have invented certain newand useful Improvements in Steam- Boiler Filters, fully described andrepresented in the following specification and the accompanyingdrawings, forming a part of the same.

The object of this invention is to automatically filter the watercontained in a steamboiler by'indueing a current from the upper part ofthe fluid in such boiler to a filter and from the filter to the lowerpart of such boiler.

My invention consists in automatically inducing such current byconnecting two pipes, respectively, with the upper and lower parts ofthe water-space in the boiler, and arranging such pipes to form anascending and descending water-circuit, in which a filter is interposed,and in which a current is induced by circulating .the feed-water througha conduit in contact with the descending pipe of such water-circuit. Thefeed-water for the boiler being colder than the contents of thewater-circuit pipes, operates to chill the descending part of thecircuit, and thereby induces a current through the same and through Theheat thus abstracted from the water in the closed circuit is fullyrestored to the boiler by theincreased temperature imparted to thefeed-water, and no such loss results from the induction of the currentin this manner as would arise if an extraneous body of fluid were usedto cool the closed circuit and the abstracted heat were not returned tothe boiler.

My construction will be understood by refefenee to the annexed drawings,showing, in

Figure 1, a transverse section of a boiler provided with myimprovements, the descending part of the water-circuit being providedwith a water-jacket, through which the feed-water supply for the boileris pumped to induce the desired circulation. Fig. 2 represents only theupper. part of the closed circuit, with a vessel interposed in the upperpart of the descending circuit-pipe, and a coil inserted in such vesseland connected with the feed-watersupply pipe.

A is the boiler; B, the water-level therein O G 0 the pipesconstitutingthe closed circuit, 0 representing the ascending part of the circuit, Cthe descending part of the same, and G a horizontal section, in whichthe filter D is interposed. The section 0 is preferably connected withthe upper portion of the waterspace within the boiler and the section 0with the lower part of such water-space.

F is a force-pump for supplying the boiler with water, G the supply-pipeleading the cold water from the same to the water-jacket E, and G thepipe leading the heated water from the jacket to the steam-boiler. Thevertical height of the pipe 0 may vary from six to twenty feet,according to the internal resistance of the filter employed, and all thepipes of the circuit would be carefully protected from radiation.

With this construction it is obvious that the water in the pipe 0 willcontain more or less of the steam-globules which abound in the waternear its surface B, and that the ascending part of the circuit mustcontain altogether the hottest fluid, owing to its immediate connectionwith theupper part of the water-space.

The descending part of the circuit to which the coolingjacket E isapplied willinecessarily contain solid water, by reason of thecondensation of all the steam-globules which it may have contained, andsuch water will evidently vary in gravity from that in the asscendingcolumn 0 in precise proportion to its reduction in temperature. Thus, ina boiler at ninety pounds pressure, thetemperature would be 320; and ifthe temperature of the feed-water were the temperature of the descendingcolumn might be reduced over 100. The proportionate reduction of volumearising from such. a reduction in temperature would be over five percent, as a cubic foot of water at 330 Fahrenheit (and correspondingpressure) weighs about fifty six and onefourth pounds, while itsweightat 230 is fiftynine and one-third pounds. Beside the differencearising from temperature, the specific gravity of the descending column,as compared with the ascending column, is greatly affected by thecondensation of the steam-bubbles, so that in practice the difference inweight between two columns ten feet in height would amount to over onepound'upon each square inch affected by the descending column.

The class of filters which I employ, and which I have frequently madethe subject of United States Letters Patent, require less than thispressure to permit the passage of the wa ter-current, and the forcegenerated by the cooling of such circuit is therefore sufficient topropel the entire contents of thewater gradually through the filter, andto deposit therein the contained impurities.

I have found that in removing the impurities from the water by filteringthe contents of the boiler, a much slower rate of filtration iseffective than if the entire body of feed-water were passed through thefilter. It would therefore be necessary only to induce a current througha closed circuit sufficient to transport the entire contents of theboiler threeor four times daily through the filter to entirely preventany deposit in the boiler.

As the feed-water usually evaporated from a boiler when in activeoperation is many times greater than this volume, it is evident that theremoval of the impurities is effected with much less expenditure ofenergy by this method than by filtering the feed-water on its passage tothe boiler. From these conditions it results that the circulation of thefeed-water in the jacket E is much more rapid than the passage of thefluid through the closed circuit or column 0, and that the abstractionof heat necessary to generate the desired currents may be more perfectlyand effectively performed than if-the movement of the fluid in thecircuit were more rapid. The filter employed for such purpose should beof akind that is readily cleansed, to remove the accumulated impurities,and its internal resistance be thus kept at the normal point,and Itherefore preferably use filters constructed as described in my PatentsNos. 273, 542 and 293,742, but any desired construction may be used, asthe nature of the filter forms no part of my present invention. Theconstruction in which the feed-water l conduit passes inside a chambercontained in the descending water-circuit is shown in Fig.

2, a coil-heater pot, 0 being interposed in the water-circuit in theupper part of the pipe G and the feed-water being pumped through thecoil h, which is connected at opposite ends with the pipe G. The coolingof the upper part of the pipe 0' secures a difference in its temperatureand its gravity throughout its entire length as effectually as if thecooling device were applied to its entire extent.

I am aware that it is not new to move the water from the water-space ofa steam-boiler through a circuit containingafilter; but, while asteam-pump, and other means have been employed to generate the necessarycurrent in such a-circuit, I am not aware that the cooling influence ofthe feed-water has ever been used to produce such current. By the use ofmy invention the use of any mechanical agency to force the water throughthe filter is entirely obviated, and the cleansing of the Waterin theboiler is effectually secured and the formation of scale preventedwithout the consumption of power or the loss of any material amount ofheat from the contents of the'boiler.

WVhat I claim as my invention is- The combination, with a steam-boiler,ofan ascending and descending water'circuit eonneeted with thewater-space within the boiler, a filter interposed in said circuit,aconduitfor the boiler feed-water in contact with the descendingwater-circuit, and a feeding device, as a pump or injector, arranged andoperated to circulate the water-supply for the boiler through the saidconduit, to simultaneously cool the descending part of the circuit andto heat the feed-water, substantially as shown and described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

. JOHN W. HYATT.

\Vitnesses: I

HENRY J. l\.[ILL ER,

CHAS. G. MCBRIDE.

